Voice site personality setting

ABSTRACT

A method is provided of setting the voice personality of a voice service site. A user browsing a voice web visits a voice site where the voice output of the site is presented using a set of voice personality characterisers with which the user is particularly comfortable. The user, in subsequently transferring to another voice service site, opts to have the voice personality that was embodied in the set of voice personality characterisers used by the site being left, transfer with the user to the new site. This transfer will typically be subject to permissions set by both the site being left and the site about to be visited.

This is a continuation application of copending U.S. patent applicationSer. No. 10/005,904, filed on Dec. 4, 2001, which is incorporated hereinby reference.

FIELD OF THE INVENTION

The present invention relates to the setting of the voice personality ofa voice service site.

BACKGROUND OF THE INVENTION

In recent years there has been an explosion in the number of servicesavailable over the World Wide Web on the public internet (generallyreferred to as the “web”), the web being composed of a myriad of pageslinked together by hyperlinks and delivered by servers on request usingthe HTTP protocol. Each page comprises content marked up with tags toenable the receiving application (typically a GUI browser) to render thepage content in the manner intended by the page author; the markuplanguage used for standard web pages is HTML (HyperText MarkupLanguage).

However, today far more people have access to a telephone than haveaccess to a computer with an Internet connection. Sales of cellphonesare outstripping PC sales so that many people have already or soon willhave a phone within reach where ever they go. As a result, there isincreasing interest in being able to access web-based services fromphones. ‘Voice Browsers’ offer the promise of allowing everyone toaccess web-based services from any phone, making it practical to accessthe Web any time and any where, whether at home, on the move, or atwork.

Voice browsers allow people to access the Web using speech synthesis,pre-recorded audio, and speech recognition. FIG. 1 of the accompanyingdrawings illustrates the general role played by a voice browser. As canbe seen, a voice browser is interposed between a user 2 and a voice pageserver 4. This server 4 holds voice service pages (text pages) that aremarked-up with tags of a voice-related markup language (or languages).When a page is requested by the user 2, it is interpreted at a top level(dialog level) by a dialog manager 7 of the voice browser 3 and outputintended for the user is passed in text form to a Text-To-Speech (TTS)converter 6 which provides appropriate voice output to the user. Uservoice input is converted to text by speech recognition module 5 of thevoice browser 3 and the dialog manager 7 determines what action is to betaken according to the received input and the directions in the originalpage. The voice input/output interface can be supplemented by keypadsand small displays.

In general terms, therefore, a voice browser can be considered as alargely software device which interprets a voice markup language andgenerate a dialog with voice output, and possibly other outputmodalities, and/or voice input, and possibly other modalities (thisdefinition derives from a working draft, dated September 2000, of theVoice browser Working Group of the World Wide Web Consortium).

Voice browsers may also be used together with graphical displays,keyboards, and pointing devices (e.g. a mouse) in order to produce arich “multimodal voice browser”. Voice interfaces and the keyboard,pointing device and display maybe used as alternate interfaces to thesame service or could be seen as being used together to give a richinterface using all these modes combined.

Some examples of devices that allow multimodal interactions could bemultimedia PC, or a communication appliance incorporating a display,keyboard, microphone and speaker/headset, an in car Voice Browser mighthave display and speech interfaces that could work together, or a Kiosk.

Some services may use all the modes together to provide an enhanced userexperience, for example, a user could touch a street map displayed on atouch sensitive display and say “Tell me how I get here?”. Some servicesmight offer alternate interfaces allowing the user flexibility whendoing different activities. For example while driving speech could beused to access services, but a passenger might used the keyboard.

FIG. 2 of the accompanying drawings shows in greater detail thecomponents of an example voice browser for handling voice pages 15marked up with tags related to four different voice markup languages,namely:

tags of a dialog markup language that serves to specify voice dialogbehaviour;

tags of a multimodal markup language that extends the dialog markuplanguage to support other input modes (keyboard, mouse, etc.) and outputmodes (large and small screens);

tags of a speech grammar markup language that serve to specify thegrammar of user input; and

tags of a speech synthesis markup language that serve to specify voicecharacteristics, types of sentences, word emphasis, etc.

When a page 15 is loaded into the voice browser, dialog manager 7determines from the dialog tags and multimodal tags what actions are tobe taken (the dialog manager being programmed to understand both thedialog and multimodal languages 19). These actions may include auxiliaryfunctions 18 (available at any time during page processing) accessiblethrough APIs and including such things as database lookups, useridentity and validation, telephone call control etc. When speech outputto the user is called for, the semantics of the output is passed, withany associated speech synthesis tags, to output channel 12 where alanguage generator 23 produces the final text to be rendered into speechby text-to-speech converter 6 and output to speaker 17. In the simplestcase, the text to be rendered into speech is fully specified in thevoice page 15 and the language generator 23 is not required forgenerating the final output text; however, in more complex cases, onlysemantic elements are passed, embedded in tags of a natural languagesemantics markup language (not depicted in FIG. 2) that is understood bythe language generator. The TTS converter 6 takes account of the speechsynthesis tags when effecting text to speech conversion for whichpurpose it is cognisant of the speech synthesis markup language 25.

The way the synthesized voice sounds (which is referred to herein as the‘voice personality’ since the synthesized voice can be made to imitate aparticular person) depends on an implicit or explicit set ofcharacterisers 30 of the process used for voice synthesis. Thus, if thevoice output is synthesised using a voie tract model, then thecharacterisers setting the voice personality are the parameters of themodel; alternatively, if the voice output is synthesised by theconcatenation of digitised voice elements such as phonemes, allophones,diphones or the like, then these elements (which may have been derivedfrom a particular celebrity) constitute the characterisers of the voicepersonality.

User voice input is received by microphone 16 and supplied to an inputchannel of the voice browser. Speech recogniser 5 generates text whichis fed to a language understanding module 21 to produce semantics of theinput for passing to the dialog manager 7. The speech recogniser 5 andlanguage understanding module 21 work according to specific lexicon andgrammar markup language 22 and, of course, take account of any grammartags related to the current input that appear in page 15. The semanticoutput to the dialog manager 7 may simply be a permitted input word ormay be more complex and include embedded tags of a natural languagesemantics markup language. The dialog manager 7 determines what actionto take next (including, for example, fetching another page) based onthe received user input and the dialog tags in the current page 15.

Any multimodal tags in the voice page 15 are used to control andinterpret multimodal input/output.

Whatever its precise form, the voice browser can be located at any pointbetween the user and the voice page server. FIGS. 3 to 5 illustratethree possibilities in the case where the voice browser functionality iskept all together; many other possibilities exist when the functionalcomponents of the voice browser are separated and located in differentlogical/physical locations.

In FIG. 3, the voice browser 3 is depicted as incorporated into anend-user system 8 (such as a PC or mobile entity) associated with user2. In this case, the voice page server 4 is connected to the voicebrowser 3 by any suitable data-capable bearer service extending acrossone or more networks 9 that serve to provide connectivity between server4 and end-user system 8. The data-capable bearer service is onlyrequired to carry text-based pages and therefore does not require a highbandwidth.

FIG. 4 shows the voice browser 3 as co-located with the voice pageserver 4. In this case, voice input/output is passed across a voicenetwork 9 between the end-user system 8 and the voice browser 3 at thevoice page server site. The fact that the voice service is embodied asvoice pages interpreted by a voice browser is not apparent to the useror network and the service could be implemented in other ways withoutthe user or network being aware.

In FIG. 5, the voice browser 3 is located in the network infrastructurebetween the end-user system 8 and the voice page server 4, voice inputand output passing between the end-user system and voice browser overone network leg, and voice-page text data passing between the voice pageserver 4 and voice browser 3 over another network leg. This arrangementhas certain advantages; in particular, by locating expensive resources(speech recognition, TTS converter) in the network, they can be used formany different users with user profiles being used to customise thevoice-browser service provided to each user.

Voice-based services are highly attractive because of their ease of use.However, the reaction of users to different voice output personalitiescan vary widely—one voice personality can encourage a certain class ofusers whilst alienating a different class.

It is an object of the present invention to provide a method andapparatus by which voice services can be presented to users with voicepersonalities with which the user is comfortable.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided amethod of setting the voice personality of a voice service site, whereinthe voice personality characterisers associated with apreviously-visited voice service site are used in presenting the voiceoutput of a currently-visited voice service site.

Typically, the voice service sites operate by serving, from voice pageservers, voice pages in the form of text with embedded voice markup tagsto a voice browser, the voice browser interpreting these pages andcarrying out speech recognition of user voice input, text to speechconversion to generate voice output, and dialog management; the voicebrowser being disposed between voice page servers and the user. In thiscase, it is the browser that manages which set of voice personalitycharacterisers is used in rendering a particular voice page.

The voice personality characterisers preferably have associated usagepermissions regarding what sites can use the characterisers. Voiceservice sites may also specify whether external voice personalitycharacterisers can be used for presenting the voice output of the site.

According to another aspect of the present invention, there is providedapparatus comprising:

voice-service access means for accessing different voice service sites;

voice-service presentation means for presenting the output from anaccessed voice service site using a voice set by a selected set of voicepersonality characterisers; and

selection means for selecting the set of voice personalitycharacterisers to be used by the voice-service presentation means topresent the currently accessed site, the selection means being operativeto enable a set of voice personality characterisers associated with apreviously-accessed voice service site to be selected for use inpresenting a currently-visited voice service site.

According to a further aspect of the present invention, there isprovided a server site holding sets of voice personality characterisersfor imparting particular voice personalities to the presentation of theoutput of voice service sites, said sets having associated usagepermissions regarding use of the sets in presenting voice sites.

BRIEF DESCRIPTION OF THE DRAWINGS

A method and apparatus embodying the invention will now be described, byway of non-limiting example, with reference to the accompanyingdiagrammatic drawings, in which:

FIG. 1 is a diagram illustrating the role of a voice browser;

FIG. 2 is a diagram showing the functional elements of a voice browserand their relationship to different types of voice markup tags;

FIG. 3 is a diagram showing a voice service implemented with voicebrowser functionality located in an end-user system;

FIG. 4 is a diagram showing a voice service implemented with voicebrowser functionality co-located with a voice page server;

FIG. 5 is a diagram showing a voice service implemented with voicebrowser functionality located in a network between the end-user systemand voice page server; and

FIG. 6 is a diagram of an embodiment of the invention in which the samevoice personality is used by two different voice services.

BEST MODE OF CARRYING OUT THE INVENTION

In the following description, voice services are described based onvoice page servers serving pages with embedded voice markup tags tovoice browsers. Unless otherwise indicated, the foregoing description ofvoice browsers, and their possible locations and access methods is to betaken as applying also to the described embodiments of the invention.Furthermore, although voice-browser based forms of voice services arepreferred, the present invention in its widest conception, is notlimited to these forms of voice service system and other suitablesystems will be apparent to persons skilled in the art.

In FIG. 6, a user 2 is depicted as using equipment 8 to browse a voiceweb, represented by voice page servers 4A and 4B, with the aid of avoice browser 3 located in the communications infrastructure 9 (thoughit may be located anywhere for present purposes).

The voice browser 3 includes a selector 33 for selecting betweenavailable sets of voice personality characteristics (abbreviated to‘VPC’ below) 30, the selected set being supplied to the text-to-speechconverter 6 (FIG. 2) of the browser to condition the voice output of thepage currently being processed by the browser. The selected VPC setimparts, for example, a celebrity voice personality to the page output.FIG. 6 shows four VPC sets, namely: a default VPC set 30D held by thebrowser and used when no other VPC set is available or desired (thedefault VPC set can be one specified by the user 2); a respective VPCset 30X and 30Y associated with voice page servers 4A and 4B; and anindependent VPC set 30Z hosted on a third party server 31.

When voice browser 3 receives a voice page for interpretation, the VPCselector 33 checks to see if the page specifies the use of anyparticular VPC set; if it does not then the default VPC set 30D isselected. If a particular VPC set is specified then VPC selector,possibly after confirming with the user, retrieves the specified VPC setto store 34 and notifies the TTS converter 6 that it should use this VPCset in rendering the page.

Thus, with reference to the FIG. 6 example, user 2 browses to voice page40 which is served by server 4A to the voice browser 3. The head portionof page 40 includes a link line 41 identifying VPC set 30X as the one tobe used (this link includes the URL of the set). VPC selector 33recognises this reference and selects the corresponding VPC set 30X overthe default VPC set 30D (see decision circle 50 in FIG. 6). VPC set 30Xis then retrieved from server 4A and saved to the store 34 from where itis used by TTS converter 6 in preference to the default VPC set 30D.

In due course, the user activates a hyperlink 42 on page 40 to fetch apage 44 from voice page server 4B. This page 44 has a VPC link 45 in itshead portion that references VPC set 30Y. However, the hyperlink 42 onpage 40 includes an attribute which indicates that the VPC set 30X canalso be used with page 44. The VPC selector 33 takes note of this and istherefore required to select between VPC set 30X and VPC set 30Y onreading the link 45 in page 44. The selection (see decision circle 55)can be effected by consulting the user, or by automatically favouringthe VPC specified in the calling page 40 or the called page 44. In thepresent case, it is assumed that the VPC set 30X is selected so that theoutput from voice page 44 is now rendered with the same voicepersonality as was used for voice page 40. The permission given by theattribute in hyperlink 42 for the use of VPC set 30X in respect of page44 is treated as being specific to that page (and possibly other pageson the same site) so when the user hyperlinks from page 44 to a yetfurther page on a different server (not shown), the option of using VPCset 30X ceases to be available to selector 33.

An example scenario showing the benefits of using the foregoingmechanism will now be given. Imagine that the user 2 is browsing thevoice site (on server 40A) of a well known celebrity cookery chef tofind a receipt for an evening meal. The feel of the voice site isfamiliar to the user from the television program hosted by thecelebrity, containing many familiar background cookery sounds andnoises. The voice output of the site (effectively the site “host”) ispresented in the voice of the celebrity, this being the voicepersonality represented by VPC set 30X. User 2 can interact with the‘host’, querying receipts, ingredients and cooking methods.

At some point during user's visit to the voice site, the user decides tobuy the list of ingredients for a chosen dish. The ‘host’ recommends awell known shopping store, where it just so happens there is a series ofspecial offers to all visitors from the celebrity's cookery voice site.

User 2 chooses to visit to the shopping store, by voice hyper-linking(hyperlink 42) to the shop's voice site (on server 40B), and requeststhe celebrity chef to accompany them through the shop. During this visitto the shop's voice site, the user hears all the distinctive sounds ofthe particular shop, as well as the voice of the celebrity (VPC set 30Xis still being used) suggesting ingredients and other items the user maylike to buy. On successfully purchasing the desired goods, the user asksthe celebrity to take the user back to the original voice site and helpthe user in cooking the meal.

At any time during the user's visit to the store site, the user is giventhe option of saying goodbye to the celebrity host in and, instead, tobe guided by the shop's assistant; in this case, the VPC selectorretrieves VPC set 30Y, saves it to store 34, and instructs the TTSconverter to use set 30Y for further speech output from server 40B.

The foregoing arrangement offers the user the advantages of a familiarvoice to guide and recommend products or services, and the resultantreassurance is of benefit both the the user and the store.

Since voice personalities, particularly of celebrities, have value butcan also be misleading if wrongly used, it is useful to provide for avariety of mechanisms for ensuring proper use of the VPC sets when thelatter are retrievable by voice browsers independently of the pages withwhich they are intended to be used. Thus, for example:

(a) each VPC set can have associated permissions specifying what pagesit can be used with (including, possibly, a generic page provided it isaccompanied by an authorisation accepted by the VPC set);

(b) a page can have associated permissions that mandates or permits theuse of a particular VPC set or a VPC set selected from a category of VPCsets;

(c) a page can have associated permissions that mandate that aparticular VPC set of class of VPC set is NOT used (this could be doneif either a particular VPC set is only suggested or no set is proposedat all);

(d) a hyperlink in a page can have associated permissions similar topermissions in (b) and/or (c).

It is the role of the VPC selector to determine what VPC set or sets canbe used having regard to all the permissions associated with the VPCsets, calling page and called page. Regardless of the statedpermissions, the VPC selector 33 always has the right to choose thedefault VPC set 30D of the browser.

Many other variants are, of course, possible to the arrangementdescribed above with reference to FIG. 6. For example, a voice site canopt to use a VPC set 30Z provided by a third-party server 31 assumingthat this is permitted by the party controlling use of the set 30Z.

Furthermore, each set of voice personality characterisers can haverespective associated phrasing style data specifying a particularsentential speaking style matching the voice personality. The phrasingstyle data is retrieved by the voice browser when retrieving thecorresponding set of voice personality characterisers, and is used tocontrol the text generated by language generator 23 (see FIG. 2) whenexpressing the semantic meaning specified in a current voice page.

What is claimed is:
 1. A method of setting the voice personality of avoice service site, wherein a set of voice personality characterisersassociated with a previously-visited voice service site is used inpresenting the voice output of a currently-visited voice service site,wherein the voice service sites operate by serving, from voice pageservers, voice pages in the form of text with embedded voice markup tagsto a voice browser, the voice browser interpreting these pages andcarrying out speech recognition of user voice input, text to speechconversion to generate voice output, and dialog management; the voicebrowser being disposed between voice page servers and the user andmanaging which set of voice personality characterisers is used duringthe text to speech conversion and wherein the set of voice personalitycharacterisers has associated permissions regarding use of the set forpresenting the voice output of voice sites; the voice browser readingand complying with these permissions.
 2. A method according to claim 1,wherein text to speech conversion at the voice browser is effected usinga voice tract model, said voice personality characterisers beingparameter values of this model.
 3. A method according to claim 1,wherein text to speech conversion at the voice browser is effected bythe concatenation of speech elements such as phonemes, allophones,diphones or the like, these latter forming said voice personalitycharacterisers.
 4. A method according to claim 1, wherein the re-use ofthe voice personality characterisers from the previously-visited sitewith the currently-visited site is subject to user opt-in or opt-out. 5.A method according to claim 1, wherein phrasing style data is associatedwith said set of voice personality characterisers, the voice browserusing this phrasing style data to generate text, for subsequentconversion to voice output, that expresses a specified semantic meaningin a particular style matched with the voice personality defined by thevoice personality characterisers.
 6. A method of setting the voicepersonality of a voice service site wherein a set of voice personalitycharacterisers associated with a previously-visited voice service siteis used in presenting the voice output of a currently-visited voiceservice site, wherein the voice service sites operate by serving, fromvoice page servers, voice pages in the form of text with embedded voicemarkup tags to a voice browser, the voice browser interpreting thesepages and carrying out speech recognition of user voice input, text tospeech conversion to generate voice output, and dialog management; thevoice browser being disposed between voice page servers and the user andmanaging which set of voice personality characterisers is used duringthe text to speech conversion and wherein the previously-visited sitespecifies permissions regarding use of the voice personalitycharacterisers associated with the site, for presenting the voice outputof other sites; the voice browser reading and complying with thesepermissions.
 7. A method according to claim 6, wherein text to speechconversion at the voice browser is effected using a voice tract model,said voice personality characterisers being parameter values of thismodel.
 8. A method according to claim 6, wherein text to speechconversion at the voice browser is effected by the concatenation ofspeech elements such as phonemes, allophones, diphones or the like,these latter forming said voice personality characterisers.
 9. A methodaccording to claim 6, wherein the re-use of the voice personalitycharacterisers from the previously-visited site with thecurrently-visited site is subject to user opt-in or opt-out.
 10. Amethod according to claim 6, wherein phrasing style data is associatedwith said set of voice personality characterisers, the voice browserusing this phrasing style data to generate text, for subsequentconversion to voice output, that expresses a specified semantic meaningin a particular style matched with the voice personality defined by thevoice personality characterisers.
 11. A method of setting the voicepersonality of a voice service site wherein a set of voice personalitycharacterisers associated with a previously-visited voice service siteis used in presenting the voice output of a currently-visited voiceservice site, wherein the voice service sites operate by serving, fromvoice page servers, voice pages in the form of text with embedded voicemarkup tags to a voice browser, the voice browser interpreting thesepages and carrying out speech recognition of user voice input, text tospeech conversion to generate voice output, and dialog management; thevoice browser being disposed between voice page servers and the user andmanaging which set of voice personality characterisers is used duringthe text to speech conversion and wherein the currently-visited sitespecifies permissions regarding the use of sets of voice personalitycharacterisers associated with other sites, for presenting the voiceoutput of said currently visited site; the voice browser reading andcomplying with these permissions.
 12. A method according to claim 11,wherein text to speech conversion at the voice browser is effected usinga voice tract model, said voice personality characterisers beingparameter values of this model.
 13. A method according to claim 11,wherein text to speech conversion at the voice browser is effected bythe concatenation of speech elements such as phonemes, allophones,diphones or the like, these latter forming said voice personalitycharacterisers.
 14. A method according to claim 11, wherein the re-useof the voice personality characterisers from the previously-visited sitewith the currently-visited site is subject to user opt-in or opt-out.15. A method according to claim 11, wherein phrasing style data isassociated with said set of voice personality characterisers, the voicebrowser using this phrasing style data to generate text, for subsequentconversion to voice output, that expresses a specified semantic meaningin a particular style matched with the voice personality defined by thevoice personality characterisers.
 16. Apparatus comprising:voice-service access means for accessing different voice service sites:voice-service presentation means for presenting the output from anaccessed voice service site using a voice set by a selected set of voicepersonality characterisers: and selection means for selecting the set ofvoice personality characterisers to be used by the voice-servicepresentation means to present the currently accessed site, the selectionmeans being operative to enable a set of voice personalitycharacterisers associated with a previously-accessed voice service siteto be selected for use in presenting a currently-visited voice servicesite and wherein the selection means includes means for reading andcomplying with usage restrictions associated with a set of voicepersonality characterisers.
 17. Apparatus according to claim 16, in theform of a voice browser for handling voice pages comprising text withembedded voice markup tags, the voice-service presentation meanscomprising a text-to-speech converter for generating voice outputaccording to the selected set of voice personality characterisers. 18.Apparatus according to claim 17, wherein the text-to-speech converter isof a type that uses concatenation of speech elements such as phonemes,allophones, diphones or the like, these latter forming said voicepersonality characterisers.
 19. Apparatus according to claim 17, whereinthe text-to-speech converter is of a type using a voice tract model,said voice personality characterisers being parameter values of thismodel.
 20. Apparatus according to claim 16, wherein the voice browserincludes a language generator arranged to use phrasing style dataassociated with the selected set of voice personality characterisers togenerate text, for subsequent conversion to voice output by thetext-to-speech converter, that expresses a specified semantic meaning ina particular style associated matched with a voice personality definedby the selected set of voice personality characterisers.
 21. Apparatuscomprising: voice-service access means for accessing different voiceservice sites; voice-service presentation means for presenting theoutput from an accessed voice service site using a voice set by aselected set of voice personality characterisers; and selection meansfor selecting the set of voice personality characterisers to be used bythe voice-service presentation means to present the currently accessedsite, the selection means being operative to enable a set of voicepersonality characterisers associated with a previously-accessed voiceservice site to be selected for use in presenting a currently-visitedvoice service site and wherein the selection means includes means forreceiving and complying with usage restrictions provided by a voiceservice site in respect of a set of voice personality characterisersassociated with the site, these usage restrictions concerning usage ofthat set of voice personality characterisers for presenting the voiceoutput of other sites.
 22. Apparatus according to claim 21, in the formof a voice browser for handling voice pages comprising text withembedded voice markup tags, the voice-service presentation meanscomprising a text-to-speech converter for generating voice outputaccording to the selected set of voice personality characterisers. 23.Apparatus according to claim 22, wherein the text-to-speech converter isof a type using a voice tract model, said voice personalitycharacterisers being parameter values of this model.
 24. Apparatusaccording to claim 22, wherein the text-to-speech converter is of a typethat uses concatenation of speech elements such as phonemes, allophones,diphones or the like, these latter forming said voice personalitycharacterisers.
 25. Apparatus according to claim 21, wherein the voicebrowser includes a language generator arranged to use phrasing styledata associated with the selected set of voice personalitycharacterisers to generate text, for subsequent conversion to voiceoutput by the text-to-speech converter, that expresses a specifiedsemantic meaning in a particular style associated matched with a voicepersonality defined by the selected set of voice personalitycharacterisers.
 26. Apparatus comprising: voice-service access means foraccessing different voice service sites; voice-service presentationmeans for presenting the output from an accessed voice service siteusing a voice set by a selected set of voice personality characterisers;and selection means for selecting the set of voice personalitycharacterisers to be used by the voice-service presentation means topresent the currently accessed site, the selection means being operativeto enable a set of voice personality characterisers associated with apreviously-accessed voice service site to be selected for use inpresenting a currently-visited voice service site and wherein theselection means is operative to read and comply with usage permissionsprovided by a currently-visited site regarding the use of sets of voicepersonality characterisers associated with other sites, for presentingthe voice output of said currently visited site.
 27. Apparatus accordingto claim 26, in the form of a voice browser for handling voice pagescomprising text with embedded voice markup tags, the voice-servicepresentation means comprising a text-to-speech converter for generatingvoice output according to the selected set of voice personalitycharacterisers.
 28. Apparatus according to claim 27, wherein thetext-to-speech converter is of a type using a voice tract model, saidvoice personality characterisers being parameter values of this model.29. Apparatus according to claim 27, wherein the text-to-speechconverter is of a type that uses concatenation of speech elements suchas phonemes, allophones, diphones or the like, these latter forming saidvoice personality characterisers.
 30. Apparatus according to claim 26,wherein the voice browser includes a language generator arranged to usephrasing style data associated with the selected set of voicepersonality characterisers to generate text, for subsequent conversionto voice output by the text-to-speech converter, that expresses aspecified semantic meaning in a particular style associated matched witha voice personality defined by the selected set of voice personalitycharacterisers.
 31. Apparatus comprising: voice-service access means foraccessing different voice service sites; voice-service presentationmeans for presenting the output from an accessed voice service siteusing a voice set by a selected set of voice personality characterisers;and selection means for selecting the set of voice personalitycharacterisers to be used by the voice-service presentation means topresent the currently accessed site, the selection means being operativeto enable a set of voice personality characterisers associated with apreviously-accessed voice service site to be selected for use inpresenting a currently-visited voice service site; and user input meansfor controlling whether a set of voice personality characterisers from apreviously-accessed site is re-used with the currently-accessed site.32. Apparatus according to claim 31, in the form of a voice browser forhandling voice pages comprising text with embedded voice markup tags,the voice-service presentation means comprising a text-to-speechconverter for generating voice output according to the selected set ofvoice personality characterisers.
 33. Apparatus according to claim 32,wherein the text-to-speech converter is of a type using a voice tractmodel, said voice personality characterisers being parameter values ofthis model.
 34. Apparatus according to claim 32, wherein thetext-to-speech converter is of a type that uses concatenation of speechelements such as phonemes, allophones, diphones or the like, theselatter forming said voice personality characterisers.
 35. Apparatusaccording to claim 31, wherein the voice browser includes a languagegenerator arranged to use phrasing style data associated with theselected set of voice personality characterisers to generate text, forsubsequent conversion to voice output by the text-to-speech converter,that expresses a specified semantic meaning in a particular styleassociated matched with a voice personality defined by the selected setof voice personality characterisers.
 36. A server site holding sets ofvoice personality characterisers for imparting particular voicepersonalities to the presentation of the output of voice service sites,said sets having associated usage permissions regarding use of the setsin presenting voice sites.
 37. A server site according to claim 36,wherein the said usage permissions associated with a said set of voicepersonality characterisers, specify what voice services are permitted touse that set of voice personality characterisers.